Cylinder-lapping machine



w. J. ALLES ET AL CYLINDER LAPPING MA CHINE Filed July 15, 1920 6'Sheets-Sheat 1 I vewi'o is I Oct. 30, 1923.

W. J. ALLES ET AL CYLINDER LAPPING MACHINE Oct. 30,1923. 1,472,379 W. J. ALLES ET AL CYLINDER LAPPI NG MACHINE Filed July 15 1920 6 Sheets- Sheet 3 a a I III I; I 0 ,9 y a f lllll l 5 62 6H 4 i I MUN/IL RIWHMIIIHIII L- A- .T-

H FT

If??? @51 1 whim 6 SheetsSheet 4 W. J. ALLES ET AL CYLINDER LAPPING MACHINE Filed July 15 Oct. 30, 1923. W. J. ALLES ET AL CYLINDER LAPPING MACHINE 1920 6 Sheets-Sheet 5 Filed July 15 Oct.

1,412,379 W. J. ALLES ET AL CYLINDER LAPPING MACHINE 6 Sheets-Sheet 6 Filed July 15 1-920 enemies on. 30,1923.

I nane WILLI J'. ALLES'AND SIDNEY C. PROBERT, 01F DETROIT, MICHIGAN, ASSIG-NORS TO DODGE BROTHERS, OF DETROIT, MICHIGAN, A CORPORATION OE MICHIGAN.

CYLINDER-DRYING ACHINE.

Application filed July 15, 1920. term] No. 3965853.

To all whomz'zf may mm.-

Be it known that we, WILLIAM Anna and SIDNEY C. Pnonnn'r, citizens of the United States, both residing at Detroit, Micha igan, have invented certain new and useful Improvements in Cylinder-Lapping Machines, of which the following is a clear,

full, and exact description.

Our invention relates to lapping machines and particularly to machines of this type which are adapted to accurately finish the inner surfaces of cylinders for internal combustion engines, and our invention has for its object the general improvement in machines of this character, whereby a more perfeet. surface may be given to the cylinder walls.

Another feature of the invention relates to an improvement in the lapping tool itself and a divisional application has been filed covering the novel structure of this tool, said divisional application bearing Serial N0. $84,054, filed July 12, 1921.

Another important feature relates to the 2 construction and mode of operation of the retaining frame or guide for holding the lap-ping tool when out of contact with the walls of the cylinder to be lapped, said frame having independently movable sections so loosely fitting therein.

Another important feature of our invention relates to the means for supplying 011 to the tool through a slush box preferably carried at the lower portion of the retaining frame above referred to, the lapping tool rea hing into the slush box near the limit of its upward movement during the lapping operation.

Another important feature relates to means for clam ing and alining the cylinder casting to e lapped during the time the lapping tool is acting upon it.

Another important feature relates to the means for connecting the supporting table with theretaining frame above referred to,

with provision for relative movement between the frameand table to allow for removal of the casting from thetable and the.

insertion of another casting to be lapped. A further important featureof the invention relates to the means for clamping the table in position, in addition to the means for elevating the table to position to engage the lappin tool.

A stil f iirther important feature of the invention relates to improved means for giving reciprocatory movement to the lapping tool or tools with a slow intermittent rotary motion, with means for varying the amount of rotary motion.

Other important features and advantages will become apparent from the following de tailed description and claims when taken in connection with the accompanying drawin s in which- 1g. 1 is a front elevation of the machine;

till

Fig. 2 is a side elevation thereof looking from the right in Fig. 1;

Fig. 3 is an enlarged fragmentary detail view illustrating the table or support upon which the cylinder casting is clamped during the lappin operation; also a portion of the retaining rame for the lapping tools;

Fig. a is a detail plan view of the table;

Figs. 5 and 6' are detail views of the clamp for securing the table to its guide osts, Fig. 5 being taken on the line 55 of ig. 3;

Fig. 7 is a fragmentary detail front elevation partly in section, illustrating the retaining frame for the lapping tool and also a part'of the mechanism forreciprocating and rotating the lapping tools;

Fig. 8 is an enlarged sectional detail View illustrating the mechanism for partly rotating the stones during the lapping operation, the section being taken on the line 88 of Fig. 7;

Fig. 9 is an enlarged sectional detail view of one of the cam plates for actuating the pawl mechanism for partly rotating the lapping tools, the section bein taken on the line 9-9 of Fig. 8 and looliing in the direction of the arrow;

Fig. 10 is an enlarged fragmentary "sectional view of the retaining frame for the lapping tools, and showing particularly the independently movable sections or rings loosely mounted therein for retaining and centralizing the lapping stones when the lapping tool is out of contact with the cyliner; B

Fig. 11 is a cross-sectional view ot the detail for supporting the cylinder casting,

Bil

the section being taken on the line 11-11,

ig. 12 is a sectional plan view of the re taining frame, the section being taken on the line 1212 of Fig. 7;

Fig. 13 is a similar view, the section being taken on the line 13-43 of Fig. 1, a part being broken away and certain other parts omitted;

Fig. 14 is a longitudinal sectional view of .one of the lapping tools, said tools all being similar in construction;

Fig. 15 is a cross-sectional view of the same taken on the line ifs-15 of Fig. 14:

Fig. 16 is a detail plan view looking in the direction of the arrow, Fig. 15, of the frame supporting the lapping stones;

Fig. 17 is a bottom plan view of the cylinder casting showing the bars which support it, said bars bein secured to the table;

' Fig. 18 is an end e evation of the parts shown in Fig. 17; and

Fig. 19 is a sectional view.

The lapping machine to which our ,in-

vention relates maybe divided into a num-' ber of parts, and the construction and operation of these parts considered under separate heads, as follows: The la ping tool; the table for supporting the cy inder casting in position to be operated upon by the lapping tool; the retainer frame for maintaining the parts of the lapping tool in proper osition at the time when the table, with its supported casting, is lowered to allow of removal of the finished casting and the substitution of another to be lapped; the means for reciprocating and rotating the lapping tools; and the means for supplying lubricant to the lapping tools during the lapping operation.

Lapping tool.

. Referring to Figs. 14, 15 and 16, each lapping tool consists of a frame 17 having a plurality of recesses 18 shown in Fig. 15 arranged symmetrically about its circumference and also having a longitudinal central bore 19. Set into each of the recesses 18 is a support or shoe 22 for a lapping stone 23. The inner wall of each recess is slotted, as shown at 20, Fig. 16, and each shoe 22 has at each end thereof a lug 21 which projects through the slot 20 and into the central bore of the frame 17. In order that the lapping stones 18 may yieldingly press against the walls of the cylinder during the lapping operation, we provide a spring 24 mounted on a spindle 25, each end of said spring carrying a ring 26 having a cam surface 27 which engages the in- I ner cam faces of the lugs 21, the spring at this time being under compression. From Fig. 14 it will be readily seen that the tend ency of the spring to expand will exert a camming action against the lugs 21, which in turn will cause radial outward pressure to be exerted against all of the stones 23. The stones are confined at the top and bottom of the tool by plates 28 and 29, plate 28 being screwed to the frame 17 by screws 30, while the plate 29 is secured to said frame by the screws 31. Said plate 29 is formed with a screw threaded socket 32, to

which a shaft may be secured and which.

will be later described, said shaft furnishing the means whereby each lapping tool-is reciprocated and rotated.

From the structure so far described it will be apparent that since the plates 28 and 29, together with the recesses 18, or at least that portion thereof carrying the lapping stones, form a straight walled pocket or recess into which a stone'fits, the tool would fall apart by reason of the spring pressure if means were not provided to prevent it. In order to prevent this, when the tool is not engaged by the walls of the cylinder to be lapped, we provide a retaining frame which will be later described.

In order to permit ready assemblage of the tool, it is desirable that all pressure on the spring be temporarily relieved, and to accomplish this we provide a flattened head 33 on the spindle 25 which is in engagement with the outside of the. cam ring 26 shown in the upper part of Fig. 14;. Engaging the lower orouter part of the lower cam ring 26 is a thimhle 34 loosely engaging the spindle 25. An adjusting nut 35 is provided, and the spindle has a screw driver slot in its head. Loosening of the nutand turning of the spindle, therefore, will resultin varying the tension of the spring, and when turned to the right the spindle will act to clamp the spring between the two cam rings 26 so as to relieve all pressure of said cam rings against the lugs 21. \Vith the pressure thus relieved, the stones may be assembled in the recesses of the frame and the tool inserted in the retaining frame, to be later described, after which the adjusting nut 35 may be unscrewed to permit the spring to exiert its pressure against the stones.

For the purpose of readily adjusting the spring tension, we provide a tool consisting of a combined screw driver and wrench. This tool is shown in Fig. 14, and consists of a sleeve 36 having an enlarged head 37 for engagement with the nut 35. Through the sleeve passes a screw driver 38 having at to prevent turning of the same. The handle is then manipulated to loosen the nut 35 until the spring 24 acquires the desired tension. The adjusting tool is removed, and the lapping tool is then in condition to functio'n.

The supporting table.

Referring now to Figs. 1 and 2, the table 43 for supporting the casting 44 to be lapped is supported and guided by members 45 situated at either side of the machine and carried by a base 46. The table 43 consists of a frame work closed at the bottom and sides, and open at the top, the said table acting, in addition .to its function as a sup port for the cylinder casting, as a receptacle into which the oil flows, after passing over the stones, and from which it is led by a telescoping connection 47 to a receptacle 48, from which it is pumped to the upper portions of the stones, as .will be subsequently described. In order that the oil may readily flow from the table into the receptacle 48, the bottom of the table is inclined,

as indicated at 49, Figs. 2 and 11. 'Guiding brackets 50, secured to the table, are bored to accurately fit the guide rods 45. Upward movement of the table is limited by brackets 52 pinned to the iide rods 45,..as shown in Figs. 1 and 3. baid brackets 52 also carry nuts 53, which limit the downward movement of the lappin tool retaining frame 54,

which is also gui ed on the rods 45, and which is connected to the table 43 by rods 55 screw threaded into the table as indicated at- 56, Fig. 1. The frame 54 has lateral pro jections through which the rods 55 loosely pass, and these rods carry nuts 57 and 58 at their upper and lower ends respectively.

The casting shown at 44 is onehaving four cylinder bores therein, although it is obvious that other forms of casting may be used with equal facility with our improved machine. This casting has a fiat top sur-' face and the lower flange 60, shown in Figs.

1, 17, 18, and 19. This cylinder casting also carries bearings for the crank shaft of theengine, in some cases five bearing points being )rovided, although in the casting shown in Big. 17 but three bearings are shown. These bearings have portions indicated at 61. Figs. 17,18 and 19, which project below the plane of the flange 60, and in order to provide a rigid support, on which the casting may be accurately located, We secure to the table parallel bars 62, fastened by screws 63 to the portions 64 projecting upwardly from the bottom plate of the table. To locate the casting accurately upon the table, a fixed pin 62 is provided, which engages with a hole in the base of the casting. At 65 is a hole in the table for receiving a removable locating pin 66, which is inserted through the base of the casting after it has been placed upon the table and slid inwardly in the proper position. These two pins, consequently, serve to establish an accurate location for the casting durin the lapping operation and prevent its acci ental dis lacement from this position.

fter the casting has been properly alined, it is securely clamped to the table, and for this'purpose advantage is taken of the fact that it is customary to cast the cylinder block in such manner that a hole is provided between adjacent pairs of cylinders, in a. four-cylinder type of engine. This hole is indicated at 67, Figs. 1 and 3, and throughthis hole is passed a beam 68 which engages a yoke 69 carried by a stud 7O screw threaded to the table at 71, Fig. 11. The other end of said beam is engaged by a link72 engaging an eye 73 carried by the table and screw threaded thereto at 74, Fig. 11. Link 72 carries a nut 75 to force the beam downwardly in contact with the cylinder casting. It will be understood that the cylinder casting is placed upon the table,

alined and clamped while the table is in its lowest position. I

' For the purpose of raising the table to a position whereby the cylinderbores may be engaged by the lapping tools, we provide a fluid pressure cylinder 76 centrally located under the table and having a piston 77, to which is connected 2). iston rod 78 suitably connected to the un er side of the table. Suitable connections are provided (not shown), whereby fluid pressure is admitted to the cylinder 76 to raise the table with its carried cylinder block. It ill, of course, be understood that any suitable means for elevating the table may be employed. As the tablestarts to rise, the lost motion between the table and the frame 54 is taken up, and the top surface of the cylinder casting engages the lower face ofthe frame 54, which face is machined so as to provide an ac= curate and tight fit between the cylinder casting and'said frame, and preferably a gasket 79 is provided to make the joint between the casting and the frame 54 oil tight. As soon as the cylinder casting encounters the frame 54, both frame and table move together. During this upward movement the cylinder lapping tools enter the respective boresin the cylinder casting. the frame 54 being urged by the action of gravity and also by the springs 80 to maintain contact with the top of the cylinder casting Said springs 80 are carried by theguide rods 45 and are situated between the upper portions of the frame 54, at each side thereof, and the bracket 81 which bracket forms part of the supporting frame of the machine. Upward movement of the table is limited by the nuts 58 carried by the lower end of rods 55 engaging the under side of brackets 52.

In order to hold the table in its elevated position, without the necessity of maintaining constant pressure in the cylinder 76,

clamps are provided, these clamps being 86 and the sleeve 87. A detachable handle 90 fitting the nut 130 is used to operate the clamp. A suitable bearing washer 88 and nut 89 are provided on one end of the spindle.

In order to balance the weight of the table and the cylinder block supported thereon and thereby relieve the cylinder 76 of the large amount of work necessary to raise the table, a counterweight 91 is providedsee Fig. 2. This weight is supported atthe end of a beam 92 pivoted at 98, the other end of said beam carrying links 94 secured to either side of the table at 95, see Fig. 1. With the cylinder block positioned as already described and the lapping tools situated within the cylinder bores, the said casting is ready for the lapping operation, but before describing in detail the manner of rotating and reciprocating the lapping tools, the lapping tool retaining frame will be described nhore in detail than has heretofore been done.

Retwiner framw.

The frame 54 for retaining the lapping tool in proper position for entry into the cylinder bores is shown in elevation in Fig. 1 and in section in Figs. 7, 10 and 12. This frame is mounted to slide on the rods and has bored therethrough as many openings as there are cylinder bores, these openings being somewhat larger than the cylinder bores,

- and each opening having a plurality of cylindrical sections or rings loosely mounted therein, said rings being indicated at 96, Figs. 7 and 10. The inside diameter of these rings is the same as that of the cylinder bore, but the rings themselves loosely fit into the openings in the frame, so that as the frame is lowered along with the table to engage the lapping tools as they emerge from the I cylinder bores there will be no binding. The rings 96 are situated in the upper portion of the frame 54, the lower portion of said frame constituting a slush box 97, said slush box having openings 98 therein which are slightly larger than the diameter of the cylinder borcs. The length of the lapping tool is considerably longer than the height of the slush box. so that the lapping tool is always positioned either within the cylinder bore or within the rings 96 duringthe lapping operation, and its parts are" always maintained in such position that the outside diameter of the stones constitutingthe lap ping tool is substantially the same as that of the cylinder bore, although the stones are beveled at their ends to provide for ready entrance of the tool both into the cylinder and into the frame. In Fig. 7, a lapping tool is shown at the left in the highest position it occupies .during a lapping operation, and at the right of said figure a tool is shown in the lowest position.

After the cylinder casting has been securely fastened to the table, pressure is admitted to the cylinder 76 and the table begins to rise. Due to the weight of the frame 54:, V

the rods 55 move through the openings in the brackets 56, the frame as remaining stationary until encountered by the top of the casting, when the springs 80 are compressed. As the table continues to rise, it encounters the nuts 58 on either side thereof and these engage the under side of brackets.

Means for reciprocating and rotating the Zapping tools.

To each of the lapping tools is secured an operating shaft 99 screw threaded into the plate 29 of the tool. as indicated at 32 in Fig. 14:. Each of these shafts carries at its upper end a gear 100, Fig. 8, said shafts being arranged in pairs, and the gears 100 of a pair of shafts intermeshing. Each pair of gears is mounted in a casing 101, Fig. 7 and each casing carries a yoke 102 to which one end of a connecting rod 103 is pivotally attached by a wrist .pin 104. Each connecting rod 103 is connected at its upper end to a crank 105 on a shaft 106. said shaft being driven by gears 107 and 108, Figs. 1 and 2. The gear 107 is carried by the shaft 106. while the gear 108 is carried bya shaft 109, said shaft 109 having a pulley attached thereto which is driven by a belt, although it is of course obvious that other means may be provided for driving shaft 109-such, for instance, as a motor connected directly to said shaft.

By the connections above described, the

lapping tools are reciproeated on rotation lfO arm 110 carries a roller 112, which engages in a slot 113. formed in a cam plate 11 1, said cam plate being pivotally secured tov the bracket 81 connected. to the frame of the machine. The cam plate 11 1 is pivoted for the purpose of adjusting the inclination of the slot 113 with respect to the vertical in order to vary the throw of the pawl 111,

and for this purpose said cam, plate is provided with a slot 115 and a clamp nut 116, the pivot of the plate also being provided with a clamp nut 117. Adjustment of the plate is efiectedb loosening of the nuts 116 and 117, as will e readily apparent.

Lubricating means for the Zapping toola- It is desirable that the lapping tools be constantly supplied with lubricant during the lapping operation, and for this purpose the slush box 97 already described, is provided with inlets 118, Fig. 12,,leading; from a common supply pipe 119, this supply pipe being connected to a pipe'120, Fi 2, by means of a 'ointed connection 121. he pipe 120 leads t to a pipe 123, so jolnted at 124, to a pipe 125 connected by a coupling 126 to a pipe 127 leading from the oil receptacle 48, already described. A pump 128, which may be of any usual and well known construction, serves to force oil throu h the pipe connections described, tothe s ush box.

After the lapping'operation has been completed, the table 43; 1s unclamped and the table lowered, the frame 54 following the table until said frame encounters the nuts 53, when the frame is arrested, but due to the lost motion connections between said table and frame, the table continues its movement until this lost motion is taken up, resulting in the castin being pulled away from the frame 54. he casting may then be unclamped and removed, and another one substituted.

From; what has been said; it. will be obvious that the adjustment of the spring 24 of the lapping tool may be readily accomplished while said toolis within the rings 96 and at a time when a cylinder casting has been removed from the table, so that the a combined screw driver and wrench may be readily inserted in any one of the openings of the frame 54.

\Vhilewe have described and shown in the drawings a preferred embodiment of our invention, it is obvious that variations may be resorted to within the scope and spirit thereof. and that partsof the device may be used without others.

Having thus described our invention,

rou h a 'ointed connection 122' 'means for retainin what we claim and desire to secure by Letters Patent is:

1. In a lapping machine, the combination with a lapping tool mounted for reciprocatory motion, of a table for supporting the cylinder casting to be lapped, said table movable from a position out of reach of the tool when in its lowest position to a position permitting the tool toenter the cylinde-r bore, and a frame for retaining the lapping tool when the table is in its lowered position, said frame movable out of contact with the tool as the table is raised.

2. In a lapping machine, the combination with a lapping tool, said tool havin lapping members so mounted that'they ten to move away from the longitudinal axis of the tool, of means for supporting a cylinder casting to be lapped, means for producing relative movement between the apping tool and casting by which the tool enters the casting andby which the tool is entirely clearof said casting, means for reciprocating the tool when Within the casting, and means for restraining the tool against the separating tendency of its members when said tool is out of the bore in the casting.

3. In a lapping machine, the combination with a lapping tool mounted for reciprocatory motion, of a table for supporting the cylinder casting to be la ped, means for moving said table and tool relatively, from a position in which the tool moves within the cylinder bore during reciprocation of said tool to a'position in which the tool is withdrawn from the 1 cylinder bore, and

the tool when so with drawn, said retainlng means releasing the tool as the said relative movement causes the tool to again enter the casting.

4. In a lapping machine, in combination, a lapping tool, said tool havin lapping stones so mounted that they tend to move away from the longitudinal axis of the tool, a frame for retaining the stones in place, a table for supporting the cylinder casting to be lapped, said table initially occupying a position such that the tool is out of contact with the cylinder bore but retained by said frame, and means for moving said frame and table in the same direction so that as the frame releases the tool the cylinder casting moves to position to receive it.

5. In a lapping machine, the combination with a support for a cylinder casting to be lapped, aframe, a slush box carried by said frame, a lapping tool, means for i reciprocating the tool within the cylinder bore, said tool in its upper position reaching into said slush box, and means for supplying oil to said box.

6. The combination with a lapping tool mounted for reciprocatory motion, of means for supporting a cylinder casting in position to receive said tool during its reciprocation, a slush-box into which said tool enters during its reciprocation, and means for supplying oil to said box.

7. The combination with a lapping tool mounted for reciprocatory motion, of a table for supporting a cylinder casting to be lapped, a slush-box, means for moving the table and casting from a position wherein the casting is free of the tool to a positionwherein the casting receives the tool within its bore, said .movement of the castlng causing its upper surface to contact with the lower surface of the' slushbox, means for securing the parts 1n the position,

whereby thereafter as the tool is recipro the support is in its lowered position said frame movable out of contact with the tool as the support is raised, said frame carrying a plurality of independently movable sections mounted loosely therein.

9. In a lapping machine, the combination with a lapping tool mounted for reciprocatory motion, of a. support for the cylinder casting to be lapped, said support movable from a position wherein the casting is out of reach of the tool when the support is in its lowest position, to a sition permitting the tool to enter the cy inder bore, and a frame movable with the support to a position to engage the tool when the support is in its lowered position but movable to release the tool as the support rises to position where the tool enters the cylinder bore.

10, In a lapping machine, the combination with a lapping tool mounted for reci rocatory motion, of a support for the cylinder casting to be lapped, said support movable from a position wherein the casting is out of reach of the tool when the support is in its lowest position, to a position permitting the tool to enter the cylinder bore, a frame movable with the support to a position to engage the tool when the sup-port is in its lowered position but movable to release the tool as the support rises to position where the tool enters the cylinder bore, and a slushbox supported between the frame and casting and partaking of movements of the frame. p

11. In a lapping machine, the combination with a lapping tool mounted for reciprocatory motion, of a support for the cylinder casting to be lapped, said sup-port movabliefrom a position wherein the casting is out of reach ofthe' tool when the support I i is in its lowest position, to a'position permitting the tool to enter the cylinder bore, a frame movable with the support to a position'to engage the tool when the support is in its lowered position but movable to release the tool as the support rises to position where the tool enters the cylinder bore and a. slush, box supported between the frame and cast ing and partaking of movements of the frame, said tool, when the support is in its upper position, reaching into said slushbox as the tool moves to its upper position during reciprocation thereof.

12. In alapping machine, the combination with a lapping tool, of a shaftcarrying said tool, a toothed wheel carried by said shaft, a pawl engaging said wheel, an arm carrying said pawl, means for reciprocating said shaft, and a cam mounted on a stationary support and having a slot engaging said pawl arm to actuate said pawl as said shaft is reciprocated. V

13. In a lapping machine, the combination with a lapping tool, of a Shaft carrying said tool, a toothedwheel carried by said shaft, a pawl engaging said wheel, an arm carrying said pawl, means for re ciprocating said shaft,ra cam mounted on a stationary support and having a slot engaging said pawl arm to actuate said pawl as said shaft is reciprocated, and means for adjusting 'said cam to vary the amount of rotation of said wheel by the pawl.

14. In a lapping machine, the combination with a lapping tool, of a table for supporting the casting to be lapped and movablefrom a position free of the-lappin tool to a position in which the lapping tocfi enters the bore of the casting, a frame for retaining the lapping tool when free of the casting, and connections between said table and frame permitting relative movement between them. a

15. In a lapping machine, the combination with a lapping tool, of a table for supporting the casting to be lapped and movable from a position free of the lap-pin tool to a position in which the'lapping too enters the bore of the casting, a frame for retaining the lapping toolwhen free of the casting, said frame having a machined face for affording a tight connection betweenit and the casting, connections between the table and frame whereby the table is lowered the frame is also lowered, and means for checking the movement of the frame before the table reaches its lowest position whereby the casting may be separated from the frame to permit its ready removal from the table. 16. In a lapping machine. the combination with a lap-ping tool. of a table for supporting the casting to be lapped and movable from a position free of the lapping enters the bore of the casting, a frame for retaining the lapping tool when free of the casting, means for cushioning the upper movement of the table and connections between said table and frame, permitting relative movement between them.

17. In a lapping machine, the combination with a lapping tool, of a table for supporting the casting to be lapped and movable from a position free of the lapping tool to a position in which the lapping tool enters the bore of the casting, a. frame for retaining the lapping tool when free of the casting, connections between said table and frame permitting relative movement between them, and means co-operating with the frame for cushioning the upward movement of the table and frame after the casting comes in contact with the frame.

18. In a lapping machine, the combination with alapping tool, of a table for supporting the casting to be lapped and movable from a position free of the lapping tool to a position in which the lapping tool enters the bore of the casting, means for elevating the table to the latter position, and means for clamping the table in its elevated position.

19. In a lapping machine, the -combination with a table for supporting the cylinder castin to be lapped, said table being open at t e top, a frame, a slush box carried by said frame, a, lapping tool, means for reciprocating the tool within the cylinder wall, said tool in its upper position reaching into said slush box, means for supplying oil to said box, said table being open at the top and having its bottom shaped to form a drain for the oil used in the lapping operation, an oil receptacle for receiving oil drained from the table, and means for pumping the oil from said receptacle to said slush box.

Signed at Detroit, Michigan, this 2nd day of July 1920.

WILLIAM J. ALLES. SIDNEY C. PROBERT.

Witnesses:

J. R. FURSE ALFRED H. KNIGHT. 

